Tailored Crafting of Core-Shell Cobalt-Hydroxides@Polyfluoroaniline Nanostructures with Strongly Coupled Interfaces and Improved Hydrophilicity to Enable Efficient Oxygen Evolution

Recently, core-shell structured nanomaterials have displayed great potential as electrocatalysts for highly efficient oxygen evolution reaction (OER). However, the controllable synthesis of a core-shell structure to achieve optimal OER performance remains a great challenge. In this work, we reported the crafting of a cobalt-hydroxides@polyfluoroaniline (Co(OH)2@PFANI) core-shell structure via a facile route of in situ polymerization. This strategy has good control over the thickness of the PFANI shell, which can be as thin as ∼1.7 nm. Because of the unique composition (i.e., high electronegative F- anion) and thin thickness of the PFANI shell, the core-shell-structured Co(OH)2@PFANI demonstrated a synergy of electronic and interface engineering, leading to the optimization of electronic structures and hydrophilicity, strongly coupled hetero-interfaces of Co(OH)2 and PFANI, highly exposed active sites, and accelerated charge transfer. As a result, the as-synthesized core-shell Co(OH)2@PFANI structure displays excellent performance for OER with a small overpotential of 265 mV at 10 mA cm-2, surpassing most reported non-noble OER electrocatalysts. Therefore, this work provides new strategies for the rational design and crafting of advanced core-shell structures for efficient electrocatalysis.